S-Adenosylmethionine protects against intrabiliary glutathione degradation induced by long-term administration of cyclosporin A in the rat

[EN] We investigate the ability of S-adenosylmethionine (SAMe) to antagonize the cyclosporine A (CyA)-induced inhibition of biliary glutathione efflux induced by long-term administration of CyA (10 mg/kg per day-CyA10 or 20 mg/kg per day-CyA20 for 4 weeks) in rats. CyA treatment reduced the liver co...

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Detalles Bibliográficos
Autores: Tuñón, María J, Palomero Labajos, Jesús, Galán Hernández, Ana Isabel, Muñoz Bermejo, María Eugenia, González Gallego, Javier, Jiménez Fernández, Rafael
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2004
País:España
Institución:Universidad de Salamanca (USAL)
Repositorio:GREDOS. Repositorio Institucional de la Universidad de Salamanca
OAI Identifier:oai:gredos.usal.es:10366/153905
Acceso en línea:http://hdl.handle.net/10366/153905
Access Level:acceso abierto
Palabra clave:S-Adenosylmethionine
Glutathione
Cyclosporin
Bile
Cyclosporins
3209 Farmacología
glutatión
ciclosporinas
bilis
S-adenosilmetionina
Descripción
Sumario:[EN] We investigate the ability of S-adenosylmethionine (SAMe) to antagonize the cyclosporine A (CyA)-induced inhibition of biliary glutathione efflux induced by long-term administration of CyA (10 mg/kg per day-CyA10 or 20 mg/kg per day-CyA20 for 4 weeks) in rats. CyA treatment reduced the liver content of total glutathione and caused a significant increase in the oxidized-to-reduced glutathione ratio and the thiobarbituric acid-reactive substances (TBARS) concentration. When the rats were concurrently treated with SAMe (10 mg/kg twice daily) and CyA, all these parameters did not significantly differ from control values. Treatment with CyA induced a significant increase in liver GGT activity that was attenuated by coadministration of SAMe. Biliary efflux of total glutathione was significantly reduced in animals treated with CyA. These changes were abolished by SAMe administration. Following inhibition of the intrabiliary catabolism of the tripeptide by acivicin, glutathione efflux rates increased to a lesser extent in animals cotreated with SAMe when compared to those receiving only CyA. The significant decrease in biliary efflux of oxidized glutathione induced by CyA was totally (S + CyA10) or partially (S + CyA20) prevented by coadministration of SAMe. Our observations confirm that SAMe cotreatment in rats antagonizes CyA-induced inhibition in the biliary efflux of glutathione and suggest that protection against intrabiliary glutathione degradation plays a major role in this protective effect.